CHEESE SYSTEMS, INC., Plaintiff/Counterclaim Defendant-Appellant,
TETRA PAK CHEESE AND POWDER SYSTEMS, INC. AND TETRA LAVAL HOLDINGS & FINANCE S.A., Defendants/Counterclaimants-Appellees. AND CUSTOM FABRICATING AND REPAIR, INC., Counterclaim Defendant-Appellant,
Appeals from the United States District Court for the Western District of Wisconsin in No. 11-CV-0021, Senior Judge Barbara B. Crabb.
John P. Fredrickson, Boyle Fredrickson, S.C., of Milwaukee, Wisconsin, argued for plaintiff/counterclaim defendant-appellant and counterclaim defendant- appellant. With him on the brief were James F. Boyle, Michael T. Griggs, and Eric J. Lalor.
Philip L. Hirschhorn, Buchanan Ingersoll & Rooney PC, of New York, New York, argued for defend-ants/counterclaimants-appellees. With him on the brief were S. Lloyd Smith and Rachel Elsby, of Alexandria, Virginia. Of counsel on the brief were Jeffrey S. Ward, Edward J. Pardon, and Shane Brunner, Merchant & Gould P.C., of Madison, Wisconsin.
Before Rader, Chief Judge, Reyna, Circuit Judge, and Davis, District Judge. [*]
Rader, Chief Judge.
In this declaratory judgment action, the United States District Court for the Western District of Wisconsin granted the summary judgment motion of Tetra Pak Cheese and Powder Systems (Tetra Pack Cheese) and Treval Laval Holdings & Finance S.A (Treval Laval) (collectively, Tetra Pak) against Cheese Systems, Inc. (CSI). In an unpublished fifty-four page opinion, the trial court determined that CSI infringed under the doctrine of equivalents and had not proven the '347 patent invalid. Cheese Sys., Inc. v. Tetra Pak Cheese and Powder Sys., Inc. and Tetra Laval Holdings & Fin. S.A., No. 11-cv-21-bbc (W.D. Wis. May 15, 2012); J.A. 1–54 (Slip Op.). By stipulation, the district court also entered a permanent injunction against CSI. Slip Op. at 55–58. Because the District Court correctly applied the law to these facts, this court affirms.
The subject matter of this patent involves commercial cheese-making vats. To make cheese, the technology combines milk and other additives in a vat. That process heats, cools, cuts, and stirs the ingredients to make cheese. At length, the ingredients solidify into a semi-solid mass called "coagulum." Slip Op. at 5.
The panels inside the vat that cut and stir the
coagulum are called "agitators, " "agitator panels, " or "paddles." Agitator panels are two-sided panels, one side with relatively sharp cutting edges, and the other side with comparatively blunt stirring edges. Electric motors drive the panels via long shafts that pass through the vat walls. During operation the electric motors rotate the shafts, causing the attached panels to stir, or to cut, the
coagulum. The panels have ample openings between the cutting or stirring blades to allow coagulum to pass through the panels as they move through the coagulum. This cutaway view from a prior art patent illustrates the general structure of a horizontal vat:
U.S. Pat. No. 4, 989, 504, Fig. 1 (the Jay ’504 Patent).
In cheese-making parlance, vats may be open or closed, and horizontal or vertical. A vat is "closed" if it has no large opening at its top. See id. at col. 1, ll. 17–25. The key distinction between horizontal and vertical cheese vats is the orientation of the agitator shafts: in vertical vats, agitator shafts are generally perpendicular to the ground, while in horizontal vats, they are generally parallel to the ground. (Figure 1, above, depicts a horizontal vat.) Horizontal vats may not lie literally horizontal to the floor, but instead may tilt slightly toward one end in order to facilitate draining. See, e.g., id. Fig. 2.
Until somewhat recently, cheese vats were predominantly oriented vertically. See id. at col. 1, ll. 25–60. However, cheese-makers recognized that vertical vats suffered efficiency and quality losses as the size of the vats increased. See id. To cure these ills, cheese makers essentially turned closed vertical vats on their sides, to become horizontal vats. See id. at col. 1, ll. 50–60.
In these horizontal vats, prior art taught that the shafts should "co-rotate" meaning turn in the same direction. Co-rotating horizontal vats improved vertical vats, but still presented problems. For instance, curds piled up on the bottom side of the vat where the agitator panels would both be moving upward. See '347 patent col. 22, ll. 44–49. Also, co-rotation caused the coagulum to flow in the same direction, which required quicker rotation of the panels in order to "catch up" with and cut the coagulum. Often the co-rotating horizontal vats suffered from inefficient cutting and other quality problems. See id. at col. 1, l. 64 to col. 2, l. 8.
The '347 patent addressed these problems with two improvements. First, the patent teaches contra-rotating the shafts (also called counter-rotating) not co-rotating. See '347 patent col. 3, ll. 28–31. The '347 patent describes counter-rotation by referring to the movement of the blades through the space where the two interconnected chambers overlap, called the "common volume:"
When shafts co-rotate, they move in opposite directions through the common volume; with counter-rotation, they move in the same direction through the common volume. With co-rotation, because the agitator panels have cutting faces on the same side, this means that when one set of agitator panels goes upward and cuts through the common volume, the other goes downward and cuts through the common volume, and vice versa in the stirring mode. Put another way, co-rotating agitator panels perform the same task (cutting or stirring), while going the opposite direction through the common volume. With counter-rotation, the panels move the same direction through the common volume: both downward, or both upward.
Second, the patent arranges the panels so that during contra-rotation, both panels present only cutting or only stirring faces to the common volume. See id. at col. 18– 17. In the claimed vat, the panels are fitted so that, even though the shafts turn in opposite directions, only cutting or only stirring action occurred as they passed through the common volume. Without this change, a vat with contra-rotating shafts would both cut and stir at the same time.
These innovations operated to ensure that only cutting or only stirring would occur as the panels move in opposite directions through the common volume. The '347 patent explains that the key is not just that the shafts contra-rotate, but instead it is the combination of contra-rotation combined with presenting only cutting or only stirring edges while moving the same direction through the common volume. Id. at 27–31. The patent explains that the panels' direction through the common volume— moving upward while cutting or downward while cutting—can be determined according to the desired qualities of the cheese product. Id. at 10–31.
The '347 patent was filed in March, 1998 and issued in November, 1999. CSI brought this declaratory judgment action in January 2011. J.A. 84. In the district court, Tetra Pak asserted that CSI infringed claims 1, 2, 3, 9, 10, 11 and 12 of the '347 patent. Claims 1 and 10 are independent. Claim 1 defines an apparatus; claim 10 a method. This appeal focuses on claim 1:
In a cheese processing vat having a pair of interconnected generally cylindrical wall portions with horizontally disposed axes, the axes of the generally cylindrical wall portions positioned in parallel horizontally spaced relation, and common opposite end walls forming with the generally cylindrical wall portions an enclosed vat containing a mixture of cheese curd solids and liquid whey, said vat having a generally oval cross section in a plane perpendicular to said axes, the improvement comprising:
An agitator panel rotably mounted on the axis of each wall portion to sweep a generally cylindrical volume;
each agitator panel including a cutting face having a plurality of sharp cutting edges disposed in a generally common first plane and an opposite stirring face having a plurality of blunt stirring edges disposed in a generally common second plane;
a drive for rotating said panels in the opposite rotational direction through the mixture in the vat such that said panels move through the common volume in the same direction, and means for mounting said panels with the respective cutting and stirring edges oriented such that during rotation only the stirring edges of the panels or only the cutting edges of the panels are moving toward the common volume and ...